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Planets, stars, and black holes all grow by consuming material from a spinning disk. While these disks may differ in size, they’re all mostly dependent on the mighty force of gravity, which keeps them spinning around the central mass. Gravity lets small clumps grow into bigger clumps. But it’s not enough to pull the whole disk into the middle in one giant clump, because angular momentum is pulling those clumps away from the center as they spin. That’s a good thing, because it means that the universe is composed of more than just large, lonely clumps of matter — it’s also why the Earth spins around the Sun instead of falling in and burning up. But that kind of central accumulation sometimes happens nonetheless, which is why we see things like planets, stars, and active black holes in the universe around us. Something seemed to be missing from the basic angular momentum vs. gravity theory. Researchers have had an idea for a while now, ...

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What time is it on Saturn? We finally know

Monday, February 11th 2019 03:47 PM

The time on Saturn For years, the length of a day on Saturn has remained an unsolved puzzle to frustrated astronomers. But now, a graduate student from the University of California Santa Cruz believes that he has finally solved the mystery. Christopher Mankovich used the planet’s rings to determine that a day on Saturn lasts for 10 hours, 33 minutes, and 38 seconds. Being a gas giant, Saturn has no solid surface that researchers can track in order to time the planet’s rotation. Because of this, it’s been tricky for them to figure out when a day starts and ends. For Jupiter, another gas giant in our solar system, scientists figured out the length of a day using the planet’s radio emissions. But Saturn’s strange magnetic field means that the same measures used on Jupiter couldn’t be used. Seismic rings Mankovich’s estimate — 10:33:38 — is faster than previous estimates from 1981 made with radio s...

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Every year, NASA recognizes astronauts who lost their lives in the pursuit of spaceflight with an official Day of Remembrance. This year, it’s celebrated February 7. And NASA Administrator Jim Bridenstine will lay a wreath at the Tomb of the Unknown Soldier in Arlington National Cemetery. Another wreath-laying ceremony will also happen at Kennedy Space Center’s Space Mirror Memorial. Both ceremonies will also include observances for NASA’s lost explorers.The three great disasters in NASA history all occurred near the same time of year, hence the timing of the Day of Remembrance, though its specific date shifts from year to year. This year, it was originally scheduled for January 31, but had to be rescheduled due to the 35-day government shutdown. Remembering the Past On January 27, 1967, a fire broke out at the Apollo 1 launchpad, killing astronauts Gus Grissom, Ed White, and Roger Chaffee.   Apollo astronauts Gus Grissom, Ed White, and Roger Chaf...

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The Milky Way is warped

Tuesday, February 5th 2019 12:36 PM

The Milky Way galaxy's disk of stars is anything but stable and flat. Instead, it becomes increasingly warped and twisted far away from the Milky Way's center, according to astronomers from National Astronomical Observatories of Chinese Academy of Sciences (NAOC). From a great distance, the galaxy would look like a thin disk of stars that orbit once every few hundred million years around its central region, where hundreds of billions of stars, together with a huge mass of dark matter, provide the gravitational 'glue' to hold it all together. But the pull of gravity becomes weaker far away from the Milky Way's inner regions. In the galaxy's far outer disk, the hydrogen atoms making up most of the Milky Way's gas disk are no longer confined to a thin plane, but they give the disk an S-like warped appearance. "It is notoriously difficult to determine distances from the sun to parts of the Milky Way's outer gas disk without having a clear idea of what that disk actually...

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The Hubble Space Telescope has discovered a small and strangely isolated dwarf galaxy just 30 million light-years away from our own Milky Way. And astronomers say the discovery was completely by accident. Luigi Bedin, of the Astronomical Observatory of Padua, and his colleagues were using Hubble to study a globular star cluster called NGC 6752. Globular clusters are tightly packed crowds of ancient stars. And when they looked at the images Hubble sent back, they noticed a small galaxy hiding behind the cluster’s brighter stars. Dwarf galaxy is a hermit The galaxy, dubbed Bedin 1 by its discoverer, is distinct in its isolation. There’s a chance this small swirl of stars may be connected to a larger nearby galaxy, but the two are far apart and it’s not clear they have ever interacted. And that’s what makes Bedin 1 so interesting for astronomers. First, most dwarf galaxies are found huddled up closer to a larger galaxy. Second, Bedin 1 shows little sign of...

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Frosty temperatures pressed much of the country this week, thanks to Arctic temperatures ushered in by the polar vortex. The deep freeze claimed at least 21 lives, suspended operations at General Motors plants, delayed some Amazon deliveries and grounded more than 1,500 flights. It was a remarkable week of weather on the ground, and it looks that way from space too: Images captured by NASA and NOAA, the National Oceanic and Atmospheric Administration, are equal parts humbling and awe-inspiring.   The satellite image embedded above, from the NOAA Environmental Visualization Laboratory, shows rows of clouds over the Great Lakes. The image was taken on Sunday, Jan. 27. "When extremely cold air moves over the unfrozen, relatively warmer lake water, columns of heated air begin to rise off the lake surface. As the rising, warmer air hits the cold air above it, the moisture condenses into cumulus clouds, then cools and sinks on either side," the NOAA ex...

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Astronomers map a black hole using "echoes" of light

Friday, February 1st 2019 11:42 AM

Black holes pepper our universe, but like their name implies, most are invisible — until something happens to change that. That something is often material flowing into the black hole. And in March 2018, one such previously invisible black hole flared to life when a flood of matter fell inward, allowing astronomers to spot and track the event, ultimately mapping out the region close to a black hole in finer detail than ever before.That work, published January 9 in Nature, was led by Erin Kara of the University of Maryland and NASA’s Goddard Space Flight Center. Kara also presented the results at a press conference the same day at the 233rd meeting of the American Astronomical Society in Seattle. Using NASA's Neutron star Interior Composition Explorer (NICER) aboard the International Space Station (ISS), the team watched the stellar-mass black hole (designated MAXI J1820+070, or J1820 for short), which flared to life March 11, every day for months. In that time, they...

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Hubble’s Camera Troubles The Hubble Space Telescope’s Wide Field Camera 3 is once again operational after issues earlier this month caused the camera to suddenly stop observations.On January 8, the telescope’s camera abruptly stopped working when it detected voltage levels outside of the expected range. That set engineers searching for what caused the problem. After investigating the issue, the team found that the voltage levels inside the camera were actually normal. Instead, data in the instrument’s telemetry circuits wasn’t accurate.  Telemetry information provides measurements of temperatures, voltages, and other vital engineering information on the function and status of the telescope and its equipment. Based on their findings, the team concluded there was a telemetry issue with the camera, while the actual voltage inside the camera was just fine. So the team reset the camera’s telemetry circuits, confirmed the instrument was wo...

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It's hard to grasp the sheer amount of astronomical data that came online this week in a 1.6-petabyte data-dump from a Hawaiian telescope, but picture 30,000 Wikipedias or 15 Libraries of Congress. At any rate, it's a lot of information, all thanks to the Panoramic Survey Telescope and Rapid Response System, or Pan-STARRS, telescope in Hawaii. Included in that data are four years' worth of photographs taken by Pan-STARRS's 1.8-meter (6 feet) telescope and 1.4-billion-pixel camera. The upload adds up to 1.6 petabytes, or 1.6 million gigabytes, of data. This is the second installment of the telescope's survey data; the first release, in 2016, totalled 2 petabytes of data. "We put the universe in a box, and everyone can take a peek," database engineer Conrad Holmberg said in a statement.  Pan-STARRS is tailored to find what astronomers call transient and variable objects — things that change over short periods of time. That's why it was able to spot ...

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Long an underfunded, fringe field of science, the search for extraterrestrial intelligence may be ready to go mainstream. Astronomer Jason Wright is determined to see that happen. At a meeting in Seattle of the American Astronomical Society in January, Wright convened “a little ragtag group in a tiny room” to plot a course for putting the scientific field, known as SETI, on NASA’s agenda. The group is writing a series of papers arguing that scientists should be searching the universe for “technosignatures” — any sign of alien technology, from radio signals to waste heat. The hope is that those papers will go into a report to Congress at the end of 2020 detailing the astronomical community’s priorities. That report, Astro 2020: Decadal Survey on Astronomy and Astrophysics, will determine which telescopes fly and which studies receive federal funding through the next decade. “The stakes are high,” says Wright, of Pen...

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